System and method for carrying out column tests under hydrostatic pressure

Abstract

A closed DELTAPstat-installation is disclosed for the potential-independent control of the pressure difference for continuous column tests under high hydrostatic pressure, as well as a pressure difference control process useful in particular for carrying out migration tests in pressure columns. By coupling two potential bottles into a closed vessel system, the gas or fluid pressure required to carry out the continuous column tests can be regulated at any desired height independently of outer influences. The pressure difference required to move the liquid is adjusted by setting the potential bottles at predeterminable heights.

What is claimed is:  
     
       1. A system for analyzing fluid flow through a packed column, comprising: 
       at least one start potential vessel, at least one target potential vessel, and at least one column, connected so as to form a closed system,  
       the start potential vessel comprising  
       a closeable fluid inlet for introducing a fluid to be analyzed,  
       a fluid outlet opening into the start potential. bottle so as to define a first level at a boundary between the fluid outlet and the interior of the start potential vessel, and  
       a first pressure pipe extending into the interior of the start potential vessel, and opening within the interior of the start potential vessel at said first level;  
       the target potential vessel comprising  
       a closeable fluid outlet for withdrawing a fluid to be analyzed,  
       a fluid inlet opening into the target potential bottle so as to define a second level at a boundary between the fluid inlet and the interior of the target potential vessel, and  
       a second pressure pipe extending into the interior of the target potential vessel, and opening within the interior of the target potential vessel at said second level;  
       a pressure medium for applying pressure to the closed system  
       the column containing porous media therein through which a fluid to be analyzed will flow, the column comprising  
       a fluid inlet and a fluid outlet;  
       the fluid outlet of the start potential vessel being in fluid connection with the fluid inlet of the column,  
       the fluid outlet of the column being in fluid connection with fluid inlet of the target potential vessel,  
       the first pressure pipe and the'second pressure pipe being in fluid connection by way of a pressure line,  
       the means for applying pressure being in fluid connection to the pressure line,  
       the first level and the second level being adjustable relative to each other, such that when the fluid inlet of the start potential vessel and the fluid oulet of the target potential vessel are closed to thereby effect a closed system, a relative adjustment of the first level and second level acts to independently control the hydraulic pressure for investigation of flow through the column under high hydrostatic pressure.  
     
     
       2. The system of  claim 1 , wherein the first pressure tube opens downwardly, and the second pressure tube opens upwardly. 
     
     
       3. The system of  claim 2 , wherein a main portion of a bottom surface of the start potential vessel defines the first level, and the bottom surface has a first reservoir formed as a downward recess in the bottom surface of the start potential vessel, the reservoir residing below the first level, the first pressure pipe extending downward, and opening at the first level at the location of the first reservoir; and wherein 
       a main portion of a top surface of the target potential vessel defines the second level, and the top surface has a second reservoir formed as an upward recess in the top surface of the target potential vessel, the reservoir residing above the second level, the second pressure pipe extending upward, and opening at the second level at the location of the second reservoir.  
     
     
       4. The system of  claim 1 , wherein the start potential vessel and the target potential vessel are vertically adjustable relative to each other, so as to effect the relative adjustment of the first level and the second level. 
     
     
       5. A method for controlling the pressure for analysis of fluid flowing through a porous media in a column under high hydrostatic pressure, comprising the steps of: 
       (1) introducing fluid through a closeable fluid inlet of a closed system, the closed system comprising, in turn, (a) a start potential vessel, (b) a column, and (c) a target potential vessel,  
       (a) the start potential vessel comprising  
       a closeable fluid inlet for introducing a fluid to be analyzed,  
       a fluid outlet opening into the start potential bottle so as to define a first level at a boundary between the fluid outlet and the interior of the start potential vessel, and  
       a first pressure pipe extending into the interior of the start potential vessel, and opening within the interior of the start potential vessel at said first level;  
       (c) the target potential vessel comprising  
       a closeable fluid outlet for withdrawing a fluid to be analyzed,  
       a fluid inlet opening into the target potential bottle so as to define a second level at a boundary between the fluid inlet and the interior of the target potential vessel, and  
       a second pressure pipe extending into the interior of the target potential vessel, and opening within the interior of the target potential vessel at said second level;  
       a pressure medium for applying pressure to the closed system  
       (b) the column containing porous media therein through which a fluid to be analyzed will flow, the column comprising  
       a fluid inlet and a fluid outlet;  
       the fluid outlet of the start potential vessel being in fluid connection with the fluid inlet of the column,  
       the fluid outlet of the column being in fluid connection with fluid inlet of the target potential vessel,  
       the first pressure pipe and the second pressure pipe being in fluid connection by way of a pressure line,  
       the means for applying pressure being in fluid connection to the pressure line,  
       the first level and the second level being adjustable relative to each other, such that when the fluid inlet of the start potential vessel and the fluid oulet of the target potential vessel are closed to thereby effect a closed system, an adjustment of the first level with respect to the second level acts to gravimetrically control the hydraulic pressure difference for investigation of flow through the column which is independent of the height of the hydrostatic pressure applied by the pressure medium, and  
       (2) adjusting the differential pressure upon the fluid by adjusting the effective difference (Δh w ) between a level (h A ) of the fluid in the start potential vessel and a level (h B ) of the fluid in the target potential vessel, according to the following formula:  
       
         
           Δ h   w   =h   B   −h   A  with Δ P   stat =ρ fluid   gΔh   w ,  
         
       
        wherein  
       Δh w  is the effective fluid height difference  
       h A  is the potential height of the fluid in the start potential bottle  
       h B  is the potential height of the fluid in the target potential bottle  
       ΔP stat  is the stationary pressure gradient  
       ρ fluid  is the fluid density, and  
       g is the acceleration due to gravity, and  
       (3) withdrawing a fluid to be analyzed.